Anyways, if you are interested here is the link. http://safemama.com/tag/sippy-cups/
Scroll all the way down to read more information on the BPA issue and details and links to other websites that are helpful.
Here is another link ( an adobe file) that I found helpful explaining the different types of plastics and what chemicals are in them:
Anyways, there are a ton of scary things out there that our children are exposed to on a daily basis, and of course it is impossible to protect them from everything. You could start researching and find so many things that are harmful and can become obsessive about it. For me, I trust that God has his hand of protection over all of my blessings, but as a mother I have a responsibility on how I care for my children and the ability to do the research for myself. If there are simple things I can do to prevent exposure and help them be healthier (ie; switching to a different bottle or cup, homemade baby food etc...) then I try my best to do that for them. Happy Reading! ;)